An Analysis Of Household Vehicle Ownership And Utilization Patterns In The United States Using The 2001 National Household Travel Survey

ABSTRACT: In addition to confirming many perceptions about the ownership, acquisition and utilization patterns of different types of vehicles, this analysis brings out some subtle differences and similarities among the vehicle types. The analysis results indicate a greater propensity to acquire and use larger vehicles such as minivans, sports utility vehicles and pickup trucks among certain socio-demographic segments of population. Increased ownership and use of vans and SUVs, and their usage as personal vehicles rather than just work vehicles warrants a need to revise vehicle type specific policies, transportation planning and control measures.

The U.S. Dept. of Transport. (DoT) Strategic Plan for FY 1997-2002 identifies 5 performance goals: safety, mobility, econ. growth & trade, human & natural environ., & nat. security. DoT conducts the NPTS to obtain info. on personal travel of U.S. households with respect to why, how, when, where from, where to, how frequently, how long, & with whom. The NPTS also provides info. by subgroups of the pop., e.g., by age, gender, race, zero-vehicle households, which allows important policy analyses of how transport. serves these groups. This report provides the results of the 1995 NPTS of travel by the civilian, non-institutionalized pop. age 5 & older.

Despite continued and growing public support of public transit, traffic congestion continues to get worse and transit ridership and service levels have grown but not sufficiently to play a more meaningful role in addressing growing travel demands. As a result, interest continues in exploring how significant service increases might provide adequate transit capacity and sufficiently attractive service levels to attract enough ridership to offset the need of households for the current number of vehicles. Similarly, policy analysts speculate that the resources saved by households with fewer autos may represent a sufficient consumer benefit to justify or offset the higher subsidy costs necessary to provide the enhanced services. While speculation on this topic is common amongst transit planners and advocates, the literature currently offers little insight into this issue. This report estimates the average costs of private car ownership in the country based on the household income and expenditures using the Bureau of Labor Statistics (BLS) data. Travel behavior as a function of vehicle ownership is explored with the National Household Travel Survey (NHTS). Analysis of the datasets is used to develop a better understanding of the economic and travel implications potentially arising as a result of households reducing their automobile ownership. As part of the study, a scenario analysis was developed using an Excel spreadsheet tool. This tool can be used by analysts to evaluate probable consequences of reduced vehicle ownership. The analysis is driven by utilizing relationships between travel behavior, transportation spending and household vehicle availability. The research offers several observations regarding the magnitude of the behavior changes that might be expected with lower vehicle ownership as well as the capacity and cost of transit expansion required to accommodate the demands.

In this report we present an analysis of the potential for reduced vehicle ownership within households based on sharing of completely self-driving vehicles that employ a "return-to-home" mode, acting as a form of shared family or household vehicle. An examination of the latest U.S. National Household Travel Survey (NHTS) data shows a general lack of trip overlap between drivers within a majority of households, opening up the possibility for a significant reduction in average vehicle ownership per household based on vehicle sharing. This reduction in ownership and an accompanying shift to vehicle sharing within each household, in the most extreme hypothetical scenario, could reduce average ownership rates by 43%, from 2.1 to 1.2 vehicles per household. Conversely, this shift would result in a 75% increase in individual vehicle usage, from 11,661 to 20,406 annual miles per vehicle. (This increase in mileage does not include the additional miles that would be generated during each "return-to-home" trip.) However, given the number of current unknowns regarding sufficient gaps between trips, future self-driving-vehicle implementation, self-driving-vehicle acceptance, and possible vehicle-sharing strategies within households, these results serve only as an upper-bound approximation of the potential for household sharing of completely self-driving vehicles.

"Census microdata are the confidential records of specific individuals and housing units from whom Decennial Census or American Community Survey responses have been obtained. The U.S. Census Bureau also draws a sample from the full set of microdata and makes these sampled records available in the Public Use Microdata Sample (PUMS) data products, so that users can develop their own tabulations. These data are being used by state departments of transportation (DOTs) and metropolitan planning organizations (MPOs) for studies, such as analyses of the commuting characteristics of population subgroups, and for supporting travel demand model and land use models."--Preface